It takes about 6 weeks to form a scar over the disc space (the annular tear) and that scar is only about 20-30% as strong as the torn annulus. You certainly might have suffered a recurrent disc herniation. Symptoms might be different than the original herniation due to the position of the new herniation and any scarring that has occurred.
The pressure of the climb will increase intradiscal pressure and possibly cause a recurrent herniation but after the 8-12 week period post-operatively, you really cannot worry if that will happen as you have no control over that situation. I tell my patients that it is like worrying that you could be hit by a meteor when you walk to your car. Could it happen-yes but there is nothing you can do to prevent it. That is, other than making sure you don’t “BLT” (bend/load/twist) all at the same time. See the section https://neckandback.com/treatments/conservative-treatment-mechanical-lower-back-disorders/ to understand the biomechanics of the lower back.
Your symptoms also could be instability as your neurosurgeon states and the vertebra is “settling” but those symptoms are typically central (in the middle of the lower back) and not unilateral (only on one side). Do you have a tension sign (pain in one side of the lower back or buttocks) when you perform a hamstring stretch?
Dr. Corenman
Donald Corenman, MD, DC is a highly-regarded spine surgeon, considered an expert in the area of neck and back pain. Trained as both a Medical Doctor and Doctor of Chiropractic, Dr. Corenman earned academic appointments as Clinical Assistant Professor and Assistant Professor of Orthopaedic Surgery at the University of Colorado Health Sciences Center, and his research on spine surgery and rehabilitation has resulted in the publication of multiple peer-reviewed articles and two books.